This invention relates to fuel tank gas caps, and, more particularly, to gas caps with some sort of assisted opening and closing device.
U.S. Pat. No. 6,035,906, the content of which is incorporated herein by reference, shows a self-closing cap for the fuel filler neck of a vehicle which is particularly adapted for use with an automatic gas tilling machine. The cap comprises a closure ring having an annular body and screw threads or bayonet lugs for detachably mounting the periphery of the annular body around the open end of the filler neck, and a closure flap assembly formed from a circular member with a nozzle receiving opening, a closure flap spring biased over the opening, and a pivotal mounting connecting the flap over the opening. The closure flap assembly includes a locking ratchet mechanism for securing the circular member over the closure ring in a selected angular position such that: the pivotal mounting is substantially 180 DEG opposite from the pivotal connection of the restrictive flap within a filler neck of a vehicle to allow a fuel nozzle from an automatic gas filling machine to be smoothly inserted into and withdrawn from the self-closing cap. The cap has a cover that snap-fits over the closure flap assembly. The top wall of the cover serves as an inclined guide face for guiding the nozzle of an automatic gas filling machine into the opening of the closure flap assembly. An overpressure valve assembly is incorporated into the circular member for releasing vapor and gases from the vehicle fuel tank when the pressure in the tank approaches a tank-rupturing level.
U.S. Pat. No. 2,169,656 describes an early system which provides for automatic opening using an electric unlock mechanism for a spring-biased-to-open cap. Although manual opening and closing is possible, the closing operation involves touching the cap, and the electrical system is grounded with the fuel tank, thus presenting a solution that is somewhat lacking from a view of safety. Further, this solution does not provide for conventional sealing of a rotatable cap.
What is needed is an actuator that permits both automatic and manual opening and closing of a fuel tank and further, essentially hands-free, hygienic operation. In particular, what is needed is a system that permits manual and automatic opening in a conventionally sealing gas cap.